U.S. patent number 5,818,920 [Application Number 08/759,182] was granted by the patent office on 1998-10-06 for apparatus for controlling communication connections based on local time.
This patent grant is currently assigned to Telefonaktiebolaget LM Ericsson. Invention is credited to M.ang.rten Rignell, Johan Sjodahl, Henrik Snellman.
United States Patent |
5,818,920 |
Rignell , et al. |
October 6, 1998 |
Apparatus for controlling communication connections based on local
time
Abstract
A method and system for preventing calls in a telecommunications
network from being connected during specified periods of time, such
as when calls to the desired communication terminal have been
forwarded to a new communication terminal in a new time zone and
the subscriber at the calling communication terminal is unaware of
the local time of the new communication terminal. According to the
invention, a prevention device is provided which informs the
calling communication terminal of the local time of the new
communication terminal prior to connection and requests the calling
communication terminal to confirm whether the communication
connection should be made, or automatically prevents the connection
from being made and informs the calling communication terminal that
the connection will not be made. The telecommunications network can
include mobile telecommunications devices.
Inventors: |
Rignell; M.ang.rten (Dalby,
SE), Sjodahl; Johan (Hjarup, SE), Snellman;
Henrik (Helsinki, FI) |
Assignee: |
Telefonaktiebolaget LM Ericsson
(Stockholm, SE)
|
Family
ID: |
25054694 |
Appl.
No.: |
08/759,182 |
Filed: |
December 4, 1996 |
Current U.S.
Class: |
379/211.02;
455/433; 368/13; 379/188; 379/200; 379/229; 379/196; 455/445;
368/10; 368/21; 455/456.4; 455/417 |
Current CPC
Class: |
H04M
3/38 (20130101); H04M 3/436 (20130101); H04M
3/42 (20130101); H04M 3/4876 (20130101) |
Current International
Class: |
H04Q
7/38 (20060101); H04M 3/42 (20060101); H04M
3/38 (20060101); H04M 3/487 (20060101); H04M
003/42 () |
Field of
Search: |
;379/210,211,219,220,221,229,265,266,309,188,196,197,198,199,200
;455/422,432,433,445 ;368/10,13,21 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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|
|
|
|
|
0 400 911 A |
|
Dec 1990 |
|
EP |
|
0516124 A2 |
|
Dec 1992 |
|
EP |
|
2 234 883 |
|
Feb 1991 |
|
GB |
|
2284965 |
|
Jun 1995 |
|
GB |
|
Other References
Patent Abstracts of Japan, vol. 013, No. 594 (E-867), 27 Dec. 1989
& JP 01 248858 A (Omron Tateisi Electron Co.), 4 Oct. 1989.
.
Patent Abstracts of Japan, vol. 016, No. 307 (E-1229), 7 Jul. 1992
& JP 04 084550 A (Oki Electric Ind. Co. Ltd.) 17 Mar. 1992.
.
Patent Abstracts of Japan, vol. 017, No. 287 (E-1374), 2 Jun. 1993
& JP 05 014489 A (Masushita Electric Ind. Co. Ltd.) 22 Jan.
1993. .
Japanese Abstract of Application No. 3-226377 (Matsushita Electric
Ind. Co. Ltd.), Aug. 1991..
|
Primary Examiner: Matar; Ahmad F.
Assistant Examiner: Wolinsky; Scott
Attorney, Agent or Firm: Burns, Doane, Swecker & Mathis,
L.L.P.
Claims
What is claimed is:
1. A telecommunications system, comprising:
a plurality of communication terminals;
a telecommunications control center for establishing communication
connections between two or more of the plurality of communication
terminals, the telecommunications center including call forwarding
means for forwarding a communication connection intended for a
desired communication terminal to a new communication terminal in
response to a control request from a subscriber associated with the
desired communication terminal; and
prevention means for selectively preventing communication
connections to the desired communication terminal or new
communication terminal from a calling communication terminal when
the prevention means determines that the calling communication
terminal is located in a different time zone than the desired
communication terminal or the new communication terminal.
2. The system of claim 1, wherein the prevention means informs the
calling communication terminal of the local time of the desired or
new communication terminal, and allows the communication connection
to be established after receiving a verification signal from the
calling communication terminal.
3. The system of claim 2, wherein the prevention means receives a
request for a communication connection from the calling terminal,
determines from a memory means the local time of the desired or new
terminal, and informs the calling terminal of the local time of the
desired or new terminal.
4. The system of claim 3, wherein the memory means is a home local
register of a public land mobile network.
5. The system of claim 4, wherein the local time information in the
home local register is derived from an identification number of a
base station or base station controller in the public land mobile
network.
6. The system of claim 1, wherein the prevention means is activated
and operable only during one or more predetermined time ranges.
7. The system of claim 6, wherein the prevention means allows
communication connections to the new or desired communication
terminal during the predetermined time range when the calling
communication terminal is located in the same time zone as the new
or desired communication terminal.
8. The system of claim 1, wherein at least one of the calling
terminal, desired terminal, and new terminal is a mobile
telecommunications device.
9. The system of claim 1, wherein the telecommunications control
center includes the public switched telephone network.
10. The system of claim 9, wherein the telecommunications control
center further includes at least one public land mobile
network.
11. The system of claim 1, wherein the prevention means informs the
calling terminal that the communication connection with the desired
or new communication terminal is prohibited.
12. The system of claim 1, wherein the prevention means is
incorporated within the telecommunications control center.
13. The system of claim 1, wherein the prevention means is
incorporated within the desired communication terminal.
14. The system of claim 1, wherein the prevention means is
incorporated within an independent device which is independent of
the calling terminal, desired terminal, new terminal, or control
center.
15. A filtering device for selectively preventing communication
connections from being established in a communication system, the
filtering device comprising:
means for exchanging communication signals with a destination
communication terminal; and
means for exchanging communication signals with the communication
system,
wherein the filtering device selectively prevents a communication
connection from being established between a calling communication
terminal and the destination communication terminal when the
filtering device determines that the calling communication terminal
and the destination communication terminal are located in different
time zones.
16. The device of claim 15, wherein the filtering device is
incorporated within a control center of the communication
system.
17. The device of claim 15, wherein the filtering device is
incorporated within the calling communication terminal or the
destination communication terminal.
18. The device of claim 15, wherein the filtering device is located
independently of the calling terminal, destination terminal, and a
control center of the communication system.
19. The device of claim 15, wherein at least one of the calling
terminal and destination terminal is a mobile communication
terminal.
20. The device of claim 15, wherein the filtering device informs
the calling communication terminal of the local time of the
destination terminal, and allows the communication connection to be
established upon receiving a verification signal from the calling
communication terminal.
21. The device of claim 20, wherein the filtering device receives a
request for a communication connection from the calling terminal,
determines from a memory means the local time of the destination
terminal, and informs the calling terminal of the local time of the
desired or new terminal.
22. The device of claim 21, wherein the memory means is a home
local register of a public land mobile network.
23. The device of claim 22, wherein local time information in the
home local register is derived from an identification number of a
base station or base station controller in the public land mobile
network.
24. The device of claim 15, wherein the filtering device is
activated and operable only during one or more predetermined time
periods.
25. The device of claim 24, wherein the filtering device allows
communication connections to the destination terminal during one of
the one or more predetermined time periods when the calling
communication terminal is located in the same time zone as the
desired terminal.
26. The device of claim 15, wherein the communication system
includes means for forwarding calls from a first destination
terminal to a second destination terminal.
27. The device of claim 15, wherein the filtering device informs
the calling terminal that the communication connection with the
destination communication terminal is prohibited.
28. The device of claim 15, wherein the filtering device is
incorporated within a conventional telephone.
29. The device of claim 15, wherein the filtering device is
incorporated within a mobile telephone.
Description
FIELD OF THE INVENTION
The invention relates to telecommunications systems and, in
particular, to telecommunications systems in which calls may be
forwarded from one subscriber location to another subscriber
location.
BACKGROUND OF THE INVENTION
In a Public Switched Telephone Network, PSTN, subscribers may
forward incoming calls from one communication terminal to another.
For example, if a first subscriber at terminal A calls a second
subscriber at terminal B, and the second subscriber has forwarded
his incoming calls from terminal B to terminal C, the PSTN will
connect the call from terminal A to terminal C and not to terminal
B. The terminals may be located in different time zones
corresponding to different local times.
In a Public Land Mobile Network, PLMN, subscribers are connected
via mobile stations. A PLMN comprises a number of base stations
with which mobile stations may be connected. The base stations may
be located in different time zones corresponding to different local
times.
A problem associated with the above communication systems in which
calls can be forwarded can be described as follows. When the first
subscriber in a first time zone calls a second subscriber who has
forwarded incoming calls from an original terminal to a new
terminal in a different time zone, the first subscriber may be
unaware of the local time of the time zone of the subscriber where
his call will end up, that is the local time corresponding to the
time zone of the new terminal. The first subscriber may then,
unknowingly, place a call to the second subscriber at an awkward
time of the day (e.g., 2:00 a.m.) for the second subscriber.
A second problem is that a subscriber calling from a first time
zone corresponding to a first local time to a mobile station may be
unaware about the local time of the time zone where the called
mobile station is currently located. The subscriber may then,
unknowingly, place a call to the mobile station at an awkward time
of day, (e.g., 2.00 a.m.).
A third problem is that a subscriber may be disturbed by incoming
calls from other subscribers of the communication system who are
placing their calls at awkward times of the day due to the
difference in local time between the calling subscribers and the
called subscriber.
To overcome problems relating to time zone differences between
calling parties and called parties, several solutions have been
suggested. For example, European Patent Application 0 516 124 A2 by
Maeda (Maeda) discloses a telephone provided with a memory for
storing names, numbers, and time information. To place a call, a
name is input to the telephone, a searching circuit determines the
telephone number and time associated with the name input into the
telephone, and the name, telephone number, and local time of the
party to be called is displayed to the user. Thus, in the Maeda
system, it is encumbent upon the user to consult the memory by
inputting the name of the party to be called. Maeda does not
disclose any means for updating the memory if the party to be
called is associated with a mobile telephone which moves between
different time zones, or if the party to be called has forwarded
calls to another location. Maeda further does not disclose any
means for preventing a call inadvertantly placed at an undesirable
time if the memory is not consulted. Therefore, the Maeda system
does not adequately prevent the connection of calls during
undesirable periods of time.
U.S. Pat. No. 5,375,104 to Ishii et al. (Ishii) discloses a system
for automatically displaying the local time of the geographic area
in which a communication device (e.g., a mobile telephone) is
located. Ishii does not suggest any means for determining the local
time of a telephone to be called, nor any means for inhibiting
calls from being connected to a mobile telephone, or to a telephone
subscriber who has forwarded calls from one telephone to another,
at an undesirable time.
UK Patent Application GB 2 294 965 A by Seppo (Seppo) discloses a
system for automatically providing a telephone user of a first
telephone with the time of day within the geographical area of a
second telephone. The telephones can be mobile telephones. However,
Seppo does not disclose any means for preventing a call placed at
an undesirable time from being completed. That is, if the first
telephone user misreads the display or does not pay attention to
the display, the call may still be completed even if occuring at an
undesirable time for the recipient of the call. Further, Seppo does
not disclose means for determining the time zone of a subscriber to
be called who has forwarded calls from a first telephone to a
second telephone.
It would be desirable for a communication system to include a means
for preventing calls placed during undesirable time periods from
being connected, where the undesirable nature of a time period
results from a subscriber having forwarded calls or from a mobile
subscriber having moved from a first time zone to a second time
zone.
SUMMARY OF THE INVENTION
To overcome the above problems, and provide further advantages, the
present invention provides for a communication system having means
for preventing calls placed at undesirable times from being
connected. According to exemplary embodiments, a communications
system in which calls can be forwarded from a desired terminal to a
new terminal, includes a prevention means for selectively
preventing communication connections to a desired or new terminal
when the calling communication terminal and the desired terminal
are located in different time zones. The prevention means can
inform the calling terminal of the local time of the desired or new
terminal, and allow the connection to be established only after
receiving verification from the calling communication terminal, or
can simply prohibit the connection from occuring during certain
time periods. Further, the prevention means can be activated during
one or more predetermined time periods. The prevention means can be
in form of a filter located within a control center, a
telecommunications device, or separately from a control center or
telecommunications device.
As a result of the present invention, calls placed at times
undesirable for the intended recipient can be automatically
inhibited or prohibited from being connected to a communication
device currently associated with the intended recipient. The
invention is particularly useful in systems having call forwarding,
mobile communications systems, or systems which incorporate both
call forwarding and mobile communications.
BRIEF DESCRIPTION OF THE DRAWINGS
A more complete understanding of the present invention can be
obtained upon reading the following Detailed Description of the
Preferred Embodiments, along with the accompanying drawings in
which like reference indicia indicate like elements, and in
which:
FIG. 1 illustrates a PSTN communication system according to the
present invention;
FIG. 2 illustrates a mobile communication system according to the
present invention operating in conjunction with the PSTN system of
FIG. 1;
FIG. 3 illustrates a mobile communication system according to the
present invention; and
FIG. 4 is a communication system according to the present
invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to FIG. 1, a first communication system 10 suitable
for implementing a first embodiment of the present invention is
shown. The system comprises a Public Switched Telephone Network
(PSTN 20) to which at least three communication terminals labeled
A, B and C are connected. The PSTN allows forwarding of calls; that
is, it is possible for a subscriber to forward a call from one
terminal to another terminal by informing the PSTN 20. If, for
example, a first subscriber at terminal A calls a second subscriber
at Terminal B and the second subscriber has forwarded incoming
calls to terminal C, the PSTN will connect the call to terminal C
and not to terminal B.
A first operational aspect of the communication system of FIG. 1
will be discussed using the example above when a first subscriber
at terminal A calls a second subscriber at terminal B and the
second subscriber has forwarded incoming calls to terminal C. When
the first subscriber calls the second subscriber at terminal B, the
PSTN 20 determines whether the second subscriber has forwarded
calls to another terminal. If the second subscriber has forwarded
the call to another terminal (in the current example to terminal
C), the PSTN 20 determines, for example from the subscriber
identification number associated with terminal C, the local time in
the time zone of terminal C (Time Zone 2). The information about
the local time in the time zone of terminal C is forwarded to the
first subscriber at terminal A where the information is presented
for example on a display 11 or as a voice request through a
loudspeaker (not shown). The PSTN 20 may now request the first
subscriber of terminal A to confirm that the call shall be
connected to subscriber C. Optionally, the PSTN 20 may request only
that the first subscriber provide a confirmation in cases when the
local time of the time zone of terminal C is within a predetermined
time range which either is a preset time range of the PSTN or has
been set by a subscriber at terminals A, B or C.
A second operational aspect of the communication system of FIG. 1
is exemplified by a first subscriber at terminal A calling a
subscriber at terminal C either directly or indirectly by calling
terminal B from which incoming calls have been forwarded to
terminal C. In a preset phase the subscriber at terminal C has
communicated to the PSTN 20 from which time zones and during which
time ranges an incoming call should be connected to terminal C
and/or from which time zones and during which time ranges an
incoming call should not be connected to terminal C. For example,
terminal C may allow incoming calls only from subscribers having
the same local time of the same time zone as terminal C during a
specified time range (e.g., from 11 p.m. to 7 a.m.). In this
manner, the subscriber at terminal C prevents subscribers who may
not be aware of the local time at terminal C to place a call to
terminal C during the night. At the same time, the subscriber at
terminal C allows subscribers in the same time zone to place a call
at any time. Such subscribers typically can be expected to be aware
of the inconvenience their call may cause to the subscriber at
terminal C because they are in the same time zone. Such an
arrangement allows subscribers in the same time zone as terminal C
to place, for example, very important calls at any time of the
day.
In a preset phase a subscriber at terminal C communicates to the
PSTN 20 restrictions on incoming calls based on the time zone of a
calling subscriber. The desired restrictions can be limited to one
or more specified periods of time.
When the subscriber at terminal A calls either terminal C directly
or calls a subscriber at terminal B who has forwarded incoming
calls to terminal C, the PSTN 20 determines whether the subscriber
at terminal A calls from a time zone and during a time period which
correspond to the restrictions earlier communicated to the PSTN 20
with respect to terminal C. Only if the subscriber at terminal A is
calling from a non-restricted time zone and at a non-restricted
time will the call be connected to terminal C. Optionally, the
calling subscriber at terminal A is informed of the restriction if
the call is not connected to terminal C.
FIG. 2 illustrates a second communication system 10 suitable for
implementing a second embodiment of the present invention. The
system comprises a Public Switched Telephone Network (PSTN) 20 to
which at least one Public Land Mobile Network (PLMN) 30 and at
least two subscriber terminals labeled A and B, respectively, are
connected. The PLMN 30 include a number of base stations 40 which
are typically located to cover different geographical areas which
may be situated in different time zones (Time Zone 2, Time Zone 3,
. . . Time Zone n). Mobile terminals, such as mobile station C in
FIG. 2, are in contact within the PLMN. The PSTN allows forwarding
of calls, that is, it is possible for a subscriber to forward a
call from one terminal to another terminal by informing the PSTN 20
accordingly. If, for example, a first subscriber calls a second
subscriber and the second subscriber has forwarded incoming calls
to a new terminal, such as mobile terminal C, the PSTN will connect
the call to mobile terminal C via the PLMN and not to the second
subscriber's original terminal. It should be understood that the
PLMN may cover a number of countries on a number of continents and
a number of time zones corresponding to different local times.
A first operational aspect of the communication system of FIG. 2
will now be discussed using the example above when the first
subscriber at terminal A calls the second subscriber at terminal B
who has forwarded incoming calls to new terminal C. When the
subscriber at terminal A calls the second subscriber at terminal B
the PSTN (20) determines whether or not the subscriber at terminal
B has forwarded calls to a new terminal. If the subscriber at
terminal B has forwarded the call to a new terminal, in the current
example to mobile terminal C, the PSTN (20) determines, for example
from a Home Local Register (HLR) (not shown) of the PLMN, the time
zone (Time Zone 2) in which mobile terminal C is currently located.
The information about the time zone can be provided to the PSTN as
part of an identification number of the base station or the base
station controller (BSC) (not shown) to which mobile terminal C is
assigned. The information about the local time of the time zone of
mobile terminal C is forwarded to the first subscriber at terminal
A where the information is presented, for example, on a display or
as a voice request through a loudspeaker (not shown). The PSTN (20)
may now request the first subscriber at terminal A to confirm that
the call should be connected to the subscriber at terminal C.
Optionally, the PSTN (20) may request the subscriber at terminal A
to provide a confirmation only in cases when the local time of the
time zone of terminal C is within a predetermined time range, which
can be set by the PSTN, the PLMN, or by a subscriber at terminals
A, B or C.
A second operational aspect of the communication system of FIG. 2
will now be discussed using the example when a subscriber at
terminal A calls a subscriber at mobile terminal C directly. When
the subscriber at terminal A calls the subscriber at mobile
terminal C the PSTN (20) determines, for example from a Home Local
Register (HLR) (not shown) of the PLMN about the time zone (Time
Zone 2) in which mobile terminal C is currently located. The
information about the time zone can be provided to the PSTN as part
of an identification number of the base station or the base station
controller (BSC) (not shown) to which mobile terminal C is
assigned. The information about the local time of the time zone of
mobile terminal C is forwarded to the first subscriber at terminal
A where the information is presented, for example, on a display or
as a voice request through a loudspeaker (not shown). The PSTN (20)
may now request the first subscriber at terminal A to confirm that
the call should be connected to the subscriber at terminal C.
Optionally, the PSTN (20) may only request the subscriber at
terminal A to provide a confirmation only in cases when the local
time of the time zone of terminal C is within a predetermined time
range, which can be set by the PSTN, the PLMN or by a subscriber at
terminal A or C.
A third operational aspect of the communication system of FIG. 2 is
exemplified by a subscriber at terminal A calling a subscriber at
terminal C either directly or indirectly by calling a subscriber at
terminal B who has forwarded incoming calls to terminal C. In a
preset phase the subscriber at terminal C can communicate to the
PLMN (30) or the PSTN (20) via the PLMN (30) from which time zones
and during which time ranges an incoming call should be connected
to terminal C and/or from which time zones and during which time
ranges an incoming call should not be connected to terminal C. For
example, terminal C may allow incoming calls only from subscribers
having the same local time of the same time zone as terminal C
during a specified time range (e.g., from 11 p.m. to 7 a.m.). In
this manner, the subscriber at terminal C prevents subscribers who
may not be aware of the local time at terminal C to place a call to
terminal C during the night. At the same time, the subscriber at
terminal C allows subscribers in the same time zone to place a call
at any time. Such subscribers typically can be expected to be aware
of the inconvenience their call may cause to the subscriber at
terminal C because they are in the same time zone. Such an
arrangement allows subscribers in the same time zone as terminal C
to place, for example, very important calls at any time of the
day.
In a preset phase, a subscriber at terminal C can communicate to
the PLMN 30 or the PSTN 20 via the PLMN 30 desired restrictions on
incoming calls based on the time zone of a calling subscriber. The
desired restrictions can be limited to one or more specified
periods of time.
When the subscriber at terminal A calls either terminal C directly
or calls a subscriber at terminal B who has forwarded incoming
calls to terminal C, the PLMN 30 and/or the PSTN 20 determines
whether the subscriber at terminal A is calling from a time zone
and during a time period which correspond to the restrictions
earlier communicated to the PLMN 30 and/or PSTN 20 with respect to
terminal C. Only if the subscriber at terminal A is calling from a
non-restricted time zone and a non-restricted time will the call be
connected to terminal C. Optionally, the calling subscriber at
terminal A can be informed of the restriction if the call is not
connected to terminal C.
A fourth operational aspect of the communication system of FIG. 2
will be discussed using as an example the situation when a
subscriber at mobile terminal C calls terminal B, calls to which
have been forwarded to terminal A. When the subscriber at mobile
terminal C calls terminal B, the PSTN 20 determines if calls to
terminal B have been forwarded to another subscriber or not. If
calls to terminal B have been forwarded to another subscriber, in
the current example to terminal A, the PSTN 20 determines, for
example from the subscriber identification number of terminal A,
the local time of the time zone of terminal A (Time Zone 1). The
information about the local time of the time zone of terminal A is
forwarded to mobile terminal C via the PLMN 30 and the information
is presented to mobile terminal C, for example on a display or as a
voice request through a loudspeaker (not shown). The PSTN 20 via
PLMN 30 may now request the subscriber at terminal C to confirm
that the call should be connected to subscriber A. Optionally, the
PSTN 20 may request a confirmation only in cases when the local
time of the time zone of terminal C is within a predetermined time
range which can be preset by the PSTN, on the PLMN, or set by a
subscriber at terminals A, B or C.
A fifth operational aspect of the communication system of FIG. 2 is
exemplified by a subscriber at mobile terminal C calling a
subscriber at terminal A either directly, or indirectly by calling
terminal B with incoming calls forwarded to terminal A. In a preset
phase, the subscriber at terminal A has communicated to the PSTN
(20) from which time zones and during which time ranges an incoming
call should be connected to terminal A and/or from which time zones
and during which time ranges an incoming call should not be
connected to terminal A. For example, terminal A may allow incoming
calls only from subscribers in the same time zone as terminal A
during the time range from 11 p.m. to 7 a.m.. In this manner, the
subscriber at terminal A prevents subscribers who may not be aware
of the local time at terminal A to place a call to terminal A
during the night. At the same time, calls from a subscriber in the
same time zone are allowed at any time. Such subscribers typically
can be expected to be aware of the inconvenience their call may
cause to the subscriber at terminal A because they are in the same
time zone as terminal A. Such an arrangement allows subscribers in
the same time zone as terminal A to place very important calls at
any time of day.
In a preset phase, a subscriber at terminal A communicates to the
PSTN 20 desired restrictions on incoming calls based on the time
zone of a calling subscriber. The desired restrictions can be
limited to one or more specified periods of time.
When the subscriber at mobile terminal C calls terminal A directly,
or calls terminal B when incoming calls are forwarded to terminal
A, the PLMN 30 and/or the PSTN 20 determine whether the call from
mobile terminal C comes from a restricted time zone and during a
restricted time period. Only if the subscriber at mobile terminal C
is calling from a non-restricted time zone and at a non-restricted
time will the call be connected to terminal A. Optionally, the
calling subscriber at mobile terminal C is informed of the
restriction if the call is not connected to terminal A.
FIG. 3 illustrates a communication system 10 suitable for
implementing a third embodiment of the present invention. The
system includes a Public Land Mobile Network (PLMN) 30 to which at
least two terminals labeled A and B, respectively, are connected.
The PLMN 30 includes a number of base stations 40 which are
positioned to cover different geographical areas which may include
different time zones (Time Zone 2, Time Zone 3, . . . Time Zone n).
Mobile stations, such as terminals A, B and C in FIG. 3, are in
contact within the PLMN. It should be understood that the PLMN may
include a number of countries on a number of continents and a
number of time zones corresponding to different local times.
In a first operational aspect of the communication system of FIG.
3, a subscriber at mobile terminal A calls the subscriber at mobile
terminal B. The PLMN 30 determines from, e.g., a Home Local
Register (HLR) (not shown) of the PLMN, the time zone (Time Zone 2)
in which mobile terminal B is currently located. The information
about the time zone can be represented as a part of an
identification number of the base station or the base station
controller (BSC) (not shown) to which mobile terminal B is
assigned. The information about the local time of the time zone of
mobile terminal B is forwarded to mobile terminal A where the
information is presented, for example, on a display or as a voice
request through a loudspeaker (not shown). The PLMN 30 may now
request the subscriber at mobile terminal A to confirm that the
call should be connected to the subscriber at mobile terminal B.
Optionally, the PLMN 30 may request confirmation only in cases when
the local time of the time zone of terminal B is within a
predetermined time range, which can be a preset time range of the
PLMN or can be a range set by a subscriber at terminal A or B.
A second operational aspect of the communication system of FIG. 3
is exemplified by a subscriber at mobile terminal A calling a
subscriber at mobile terminal B. In a preset phase, the subscriber
at mobile terminal B communicates to the PLMN 30 from which time
zones and during which time ranges an incoming call should be
connected to mobile terminal B and/or from which time zones and
during which time ranges an incoming call should not be connected
to mobile terminal B. For example, the subscriber at mobile
terminal B may allow incoming calls only from subscribers in the
same time zone as mobile terminal B during a specified time range;
e.g., from 11 p.m. to 7 a.m.. In this manner, the subscriber at
mobile terminal B prevents subscribers who may not be aware of the
local time at mobile terminal B to place a call to mobile terminal
B during the night. At the same time, the subscriber at mobile
terminal B allows subscribers in the same time zone to call at any
time. Such subscribers can typically be expected to be aware of the
inconvenience their call may cause the subscriber at mobile
terminal B because they are in the same time zone as mobile
terminal B. In fact, such an arrangement allows subscribers in the
same time zone as mobile terminal B to place, for example, very
important calls independently of the time of day.
In a preset phase, the subscriber at mobile terminal B communicates
to the PLMN 30 desired restrictions on incoming calls based on the
time zone of a calling subscriber. The desired restrictions can be
limited to one or more specified periods of time.
When the subscriber at mobile terminal A calls the subscriber at
mobile terminal B, the PLMN 30 checks whether the call originates
from a restricted time zone and during a restricted time period.
Only if the subscriber at mobile terminal A is calling from a
non-restricted time zone and at a non-restricted time will the call
be connected to mobile terminal B. The calling subscriber can be
informed of the restriction if the call is not connected to mobile
terminal B.
FIG. 4 illustrates a communication system (10) according to a
fourth embodiment of the present invention. The system includes a
Public Land Mobile Network (PLMN) and/or a Public Switched
Telephone Network, PSTN 60 to which at least two terminals labeled
A and B, respectively, are connected. In this case a filter unit 50
is connected between terminal B and the PLMN/PSTN.
In operation when a subscriber at terminal A calls a subscriber at
terminal B, the filter unit 50 answers the call and informs the
calling subscriber by a voice message of the local time of the
subscriber at terminal B. The filter unit may also inform the
calling subscriber that the call can be connected only if the
calling subscriber gives a predetermined voice message or activates
a certain key or key sequence at terminal A. In this case, and if
the calling subscriber provides the predetermined voice message or
activates the correct key or keys, the call will be connected to
terminal B.
Assume that a first subscriber has enabled the filter and set the
period to block incoming calls between 10 pm and 8 am. A second
subscriber calling the first subscriber in the period between 10 pm
and 8 am will receive a message (on a display or as a voice
message) that the filter is active. The second subscriber can then
"override" the filter by simply holding the line for a
predetermined period of time (e.g. 3 seconds). Alternatively the
second subscriber is connected to an answering machine or an
answering service in the PLMN/PSTN where he can leave a message.
This connection may be made dependent on a signal, such as the
activating of a key or a voice message, from the second
subscriber.
It should be understood that the filter unit 50 may be programmed
by the subscriber at terminal B to inform a calling subscriber
about the local time only during preset time intervals.
Furthermore, the filter unit 50 may be programmed to the subscriber
at terminal B to allow a call to be connected when the calling
subscriber provides the required voice message or activates the
required key or keys only during preset time intervals. If the
filter unit 50 is set in this mode, the terminal unit (phone) may
be used as the required input/output device or the filter unit 50
may be provided with its own input/output device. It should be
understood that the filter unit may be built into the PSTN and/or
the PLMN or it may be built into the terminal unit (phone) or it
may be realized as a separate unit which a subscriber connects
between the socket for his connections to the PSTN and his terminal
unit. The filter unit may comprise a real-time clock as a base for
the local time or it may receive the local time from the PSTN
and/or the PLMN. In an alternative embodiment, the filter unit 50
as discussed above may be built into a mobile phone.
While the foregoing description includes many details and
specificities, it is to be understood that these are for purposes
of illustration only, and are not to be construed as limitations of
the invention. Numerous modifications will be readily apparent to
those of ordinary skill in the art which do not depart from the
scope and spirit of the invention, as defined by the following
claims and their legal equivalents.
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